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31.
Découverte de microfaunes de l'Albienmoyen et supérieur dans la vallée de Joux (Jura Vaudois,Suisse)
The discovery of Foraminifera and Ostracodesin the dark green, sandy-glauconitic marl clay in the Joux Valley (in the Vaudois Jura) suggests to date these sediments Middle and Upper Albian. The Ostracode associations are similar to those found in the Paris Basin, but different from those which characterize the subalpine region. 相似文献
32.
Henri Fontaine 《Geobios》1977,10(3):471-477
After a few remarks on the coral fauna in deposits near La Roquelle in Cotentin, the genus Iowaphyllum is identifiedfor the first time in France. One species (I. bohemicum) is described here; it brings new paleogeographic and stratigraphic data. 相似文献
33.
On the continental Copepod fauna of Morocco 总被引:4,自引:4,他引:0
A series of samples, collected in different parts of Morocco, contained 26 species and one subspecies of Copepoda. Ten among these are new to the fauna of Morocco and one is new to Science. Two species (Eucyclops hadjebensis Kiefer and Mixodiaptomus laciniatus atlantis Kiefer) are endemic to Morocco; Afrocyclops gibsoni Brady and Thermocyclops schuurmanae Kiefer are Ethiopan species. The former reaches its limit of Northern extent East of the Atlas mountains; the latter is a pluvial relict. The remaining species have either a cosmopolitan, circummediterranean or North-African distribution, with the exception of Cyclops abyssorum mauretaniae which is a southern element of the Eurasiatic genus Cyclops. Its taxonomical status is reviewed in some detail. Thermocyclops infrequens Kiefer is synonymized with T. schuurmanae Kiefer. It is concluded that the largest gaps in our knowledge of the Copepoda of Morocco are now in the group of the Harpacticoida.Contribution no. 14 of the biological expedition of the University of Gent (Belgium) to Morocco, July–August 1971 相似文献
34.
Summary The addition of serum to quiescent NIH 3T3 mouse cell cultures resulted in a 10- to 20-fold increase of Rb influx which was resistant to ouabain, and only a three- to fourfold activation of ouabain-sensitive Rb influx. Stimulation of the ouabain-resistant Rb influx following serum addition reached its maximum within 2 min. The stimulation of ouabain-resistant Rb influx was a result ofV
m increase while theK
m for Rb was unchanged. Ouabain-resistant Rb influx, after serum addition, was resistant to amiloride and sensitive to ethacrinic acid. Replacing chloride in the medium by NO3
–, CO3
– and CH3COO– resulted in a drastic decrease in the ouabain-resistant Rb influx. It appeared, therefore, that the ouabain-resistant Rb influx in NIH 3T3 cells was Cl–-dependent. 相似文献
35.
Michael W. Fountain Robert Chiovetti Henri Kercret David O. Parrish Jere P. Segrest 《生物化学与生物物理学报:生物膜》1980,596(3):420-425
A method has been developed for the rapid separation of cells in suspension from non-cell associated lipid vesicles in various assays for vesicle-cell interaction. Separation is achieved on a discontinuous Ficoll-Paque gradient. Cells and free vesicles are totally separated, as evidenced by both radiolabelled vesicles, and vesicles containing the fluorescent dye 6-carboxyfluorescein. The main advantages of this method are the rapidity, efficacy, and gentleness of the separation. Viability of the cells remains consistently high (greater than 96%) throughout the separation. Since this method involves a one-step centrifugation, it precludes the necessity for repeated washings of cells which have been incubated with lipid vesicles. 相似文献
36.
van Onckelen Henri A.; Caubergs Roland; de Greef Jan A. 《Plant & cell physiology》1977,18(5):1029-1040
The influence of light and endogenous plant-growth regulatorson the evolution of - and ß-amylases in cotyledonsof Phaseolus vulgaris L. was investigated. Both enzymes, whichare not present in ungerminated seeds, appear during germinationof intact seedlings or incubation of excised cotyledons. -Amylaseactivity decreases upon exposure to light. This inhibition iscorrelated with a drastic increase in chlorophyll content anda change in the endogenous gibberellin-inhibitor balance. ß-Amylaseactivity was not affected by light treatment but was by thepresence of endogenous cytokinins. (Received February 3, 1977; ) 相似文献
37.
Bacteriophage MS2 RNA: A correlation between the stability of the codon: Anticodon interaction and the choice of code words 总被引:9,自引:0,他引:9
Henri Grosjean David Sankoff Willy Min Jou Walter Fiers R. J. Cedergren 《Journal of molecular evolution》1978,12(2):113-119
Summary The non-random distribution of degenerate code words in Bacteriophage MS2 RNA can be explained partially by considerations of the stability of the codon-anticodon complex in prokaryotic systems. Supporting this hypothesis we note that wobble codons are positively selected in codons having G and/or C in the first two positions. In contrast, wobble codons are statitically less likely in codons composed of A and U in the first two positions. Analyses of nucleotides adjacent to 5 and 3 ends of codons indicate a nonrandom distribution as well. It is thus likely that some elements of RNA evolution are independent of the structural needs of the RNA itself and of the translated protein product.This work was supported by grants from the Belgian Government Actions concertées - Gekon-certéerde Acties, N.F.W.O. and F.K.F.O. as well as from le Ministère de l'éducation du Québec. A preliminary report of this work was given at the EMBO ribosome workshop, Brussels 1976 相似文献
38.
Cyst hatching in Anostraca accelerated by retinoic acid,amplified by Calcium Ionophore A23187, and inhibited by Calcium-channel blockers 总被引:1,自引:1,他引:0
Cyst hatching, under standardized conditions, of the Anostracan species Thamnocephalus platyurus and Streptocephalus dichotomus was significantly accelerated but not increased by applying the morphogen retinoic acid (RA). Cyst hatching was enhanced but not accelerated by artificially increasing the inflow of Ca2+ to the embryonic cells, using Calcium Ionophore A 23 187. Cyst hatching was accelerated and amplified, to a level in excess of the summed effects of each treatment, by a combined application of RA and ionophore. It was inhibited almost quantitatively by the Calcium-channel blockers Nifedipin and Verapamil. The significance of these findings is discussed. 相似文献
39.
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